Nonwoven articles comprising abrasive particles

ABSTRACT

A dry nonwoven article comprising a web of fibers and abrasive particles wherein the abrasive particles have a mean solidity below 0.85.

TECHNICAL FIELD

The invention relates to the field of dry nonwoven articles comprisingabrasive particles. The invention relates particularly to nonwovenarticles comprising abrasive particles for use in surface cleaning.

BACKGROUND OF THE INVENTION

Articles containing abrasive components such as particles are known inthe art. Such articles may be used for cleaning a variety of surfaces;especially those surfaces that tend to become soiled with difficulty toremove stains and soils.

Such articles may comprise a substrate and a plurality of abrasiveparticles where the abrasive particles are disposed either on thesurface of the substrate or within the substrate such that the abrasiveparticles at least partially protrude from at least one surface and thesubstrate during use. Examples of substrates that might include suchabrasive particles include nonwoven articles including disposable wipes,paper towel, floor wipes, home care napkins, beauty care napkins, andbaby wipes. Examples of abrasive particles include inorganic particlessuch as carbonate salt, clay, silica, silicate, shale ash, perliteand/or organic particles such as polymeric beads comprised ofpolypropylene, PVC, melamine, urea, polyacrylate and derivatives.

When used as a component of a nonwoven article, many commonly knownabrasive particles may not be fully satisfactory. The abrasive particlesmay separate from the rest of the article, in particular while scouringis exercised with the article. This may lead to inefficient cleaning andto unacceptable deposition of particles on the surface to be cleaned.Separately, the abrasive particles may move or “roll” while scouring,relative to the substrate, again leading to a loss of their abrasivecleaning efficiency.

The inventors have discovered that this could be alleviated by the useof particles having specific shape. This shape may be expressed as the“Solidity” of the particles. Selecting particles of the specifiedsolidity may lead to both improvements in extent to which the particlesare retained by the substrate, and improvements in cleaning bypreventing “rolling” of the particles and maintaining the orientation ofthe particles, relative to the substrate and therefore relative to thesurface being cleaned, during scouring.

Also, maintaining the orientation of the particles relative to thesubstrate may generate less damage to the surface to be cleaned.

SUMMARY OF THE INVENTION

In one aspect, a dry nonwoven article comprises a web of fibers andabrasive particles at least partially embedded in the web, wherein theabrasive particles have a mean solidity below about 0.85.

The articles according to the invention have an improved retention ofthe abrasive particles, in particular during scouring. The specificshape of the abrasive particles leads to an improved maintenance of theparticles within the web of fibers as well as improved maintenance ofthe orientation of the particles relative to the substrate, andtherefore relative to the surface being cleaned, which may in turnimprove the cleaning properties while having limited damage to thesurface to be cleaned. Without being bound by theory, the inventorsbelieve that the improved cleaning efficiency is linked to the fact thatthe specific shape of the particles limits their rolling within the webof fibers while scouring.

DESCRIPTION OF THE DRAWINGS

FIG. 1 is a picture of a hard surface wipe as described in example 2.

FIG. 2 is a picture of a hard surface wipe as described in example 3.

FIG. 3 is a picture of a floor wipe as described in example 5.

FIG. 4 is a picture of a baby toilet wipe as described in example 7.

FIG. 5 is a picture of a disposable hard surface wipe as described inexample 8.

FIG. 6 is a picture of a disposable hard surface wipe as described inexample 8.

FIG. 7 is a picture of a disposable towel as described in example 9.

DETAILED DESCRIPTION OF THE INVENTION

All percentages, ratios and proportions used herein are by weightpercent unless otherwise specified.

As used herein, the mean Equivalent Circle Diameter (ECD) is measuredaccording to ASTM F1877-05 Section 11.3.2 or similar to thearea-equivalent diameter (ISO 9276-6:2008(E) section 7). The mean ECD ofparticle population is calculated as the volume-weighted average ofrespective ECD of a particle population of at least about 1000particles, or at least about 10,000 particles, or above about 50,000particles, or above about 100,000 particles after excluding from themeasurement and calculation the data of particles having area-equivalentdiameter (ECD) of below about 10 micrometers.

As used herein, Form factor is a mesoshape descriptor and is aquantitative, 2-dimension image analysis shape description and is beingmeasured according to ISO 9276-6:2008(E) section 8.2. Form factor issometimes described in literature as being the difference between aparticle's shape and a perfect sphere. Form factor values range from 0to 1, where a form factor of 1 describes a perfectly spherical particleor disc-shaped particle as measured in a two dimensional projectedimage.

${{Form}\mspace{14mu} {Factor}} = \frac{4\pi \; A}{P^{2}}$

where A is projection area, which is 2D descriptor and P is the lengthof the perimeter of the particle. The applicants refer herein to Formfactor as being volume-weighted mean Form Factor extracted from adistribution of particle measurements. As used herein, the MOHS hardnessscale refers to an internationally recognized scale for measuring thehardness of a compound versus a compound of known hardness, seeEncyclopedia of Chemical Technology, Kirk-Othmer, 4 th Edition Vol 1,page 18 or Lide, D. R (ed) CRC Handbook of Chemistry and Physics, 73 rdedition, Boca Raton, Fla.: The Rubber Company, 1992-1993. Many MOHS Testkits are commercially available containing material with known MOHShardness. For measurement and selection of abrasive material withselected MOHS hardness, it is recommended to execute the MOHS hardnessmeasurement with un-shaped particles e.g.: with spherical or granularforms of the abrasive material since MOHS measurement of shapedparticles will provide erroneous results.

As used herein, the Shore® D hardness of the materials may be determinedaccording to ASTM D2240-05 (2010). Shore® D hardness measurement may becarried out by using an ASTM durometer, such as the Type D StyleDurometer available from Pacific Transducer Corp. of Los Angeles,Calif., or from ELECTROMATIC Equipment Co., Inc. 600 Oakland AveCedarhurst, N.Y. 11516.

As used herein, Solidity is a quantitative, 2-dimensional image analysisshape description, and is being measured according to ISO 9276-6:2008(E)section 8.2 as implemented via the Occhio Nano 500 ParticleCharacterisation Instrument with its accompanying software Callistroversion 25 (Occhio s.a. Liege, Belgium). While particle shape can bedefined in 3-dimension with dedicated analytical technique, theapplicant has found, that the characterization of the particles shape in2-dimension is most relevant and correlates with the abrasiveperformance of the cleaning particles. During the particle shapeanalysis protocol, the particles are orientated toward the surface—viagravity deposition—similarly to the expected particle orientation duringthe cleaning process. Hence, the object of the present invention regardsthe characterization of 2-D shape of a particle/particle population asdefined by the projection of its shape on the surface on which theparticle/particle population is deposited.

The non-spherical particle herein has at least one edge or surfacehaving a concave curvature. Solidity is a mesoshape parameter, whichdescribes the overall concavity of a particle or particle population.Solidity values range from 0 to 1, where a solidity number of 1describes a non-concave particle, as measured in literature as being:

Solidity=A/Ac

Where A is the projected area of the particle and Ac is the area of theconvex hull (envelope) bounding the projection of the particle. Theapplicants refer herein to solidity as being volume-weighted meansolidity extracted from a distribution of particle measurements.

As used herein, the terms “mean solidity”, or “mean Form factor”, meanthe volume-weighted average of the solidity, or Form Factor values froma population of at least about 1000 particles, or at least about 10,000particles, or above about 50,000 particles, or above about 100,000particles, after excluding from the measurement and calculation, thesolidity or form factor data of particles having area-equivalentdiameter (ECD) of below 10 micrometers.

As used herein, the Vickers hardness HV is measured at 23° C. accordingto standard methods ISO 14577-1, ISO 14577-2, ISO 14577-3. The Vickershardness is measured from a solid block of the raw material at least 2mm in thickness. The Vickers hardness micro indentation measurement iscarried out by using the Micro-Hardness Tester (MHT), manufactured byCSM Instruments SA, Peseux, Switzerland. As per the ISO 14577instructions, the test surface should be flat and smooth, having aroughness (Ra) value less than 5% of the maximum indenter penetrationdepth. For a 200 micrometer maximum depth this equates to a Ra valueless than 10 micrometer. As per ISO 14577, such a surface may beprepared by any suitable means, which may include cutting the block oftest material with a new sharp microtome or scalpel blade, grinding,polishing or by casting melted material onto a flat, smooth casting formand allowing it to thoroughly solidify prior testing.

Suitable general settings for the Micro-Hardness Tester (MHT) are asfollows:

Control mode: Displacement, ContinuousMaximum displacement: 200 μiη Approach speed: 20 nm/sZero point determination: at contactHold period to measure thermal drift at contact: 60 sForce application time: 30 sFrequency of data logging: at least every secondHold time at maximum force: 30 sForce removal time: 30 sShape/Material of intender tip: Vickers Pyramid Shape/Diamond Tip

As used herein, the term nonwoven means: a manufactured sheet, web orbatt of directionally or randomly orientated fibers, bonded by friction,and/or cohesion and/or adhesion, excluding paper and products which arewoven, knitted, tufted, stitch-bonded incorporating binding yarns orfilaments, or felted by wet-milling, whether or not additionallyneedled. The fibers may be of natural or man-made origin and may bestaple or continuous filaments or be formed in situ. Commerciallyavailable fibers have diameters ranging from less than about 0.001 mm tomore than about 0.2 mm and they come in several different forms: shortfibers (known as staple, or chopped), continuous single fibers(filaments or monofilaments), untwisted bundles of continuous filaments(tow), and twisted bundles of continuous filaments (yarn). Nonwovenfabrics can be formed by many processes such as meltblowing,spunbonding, solvent spinning, electrospinning, and carding. The basisweight of nonwoven fabrics is usually expressed in grams per squaremeter (gsm).

A nonwoven article comprises a web of fibers and abrasive particles.

The Web of Fibers

The web of fibers may comprise synthetic fibers and/or natural fibers.The fibers may be water insoluble.

Synthetic fibers suitable for use in the substrate of the disclosed wipemay include, but are not limited to, nylons, polyesters, acrylics,olefin fibers such as polyethylene and polypropylene, carbon fibers,glass fibers, metal fibers.

The natural fibers may be cellulose-containing fibers including, but notlimited to, cotton fiber, flax fiber, hemp fiber, sisal fiber, jutefiber, kenaf fiber, bamboo fiber, coconut fiber, and wood pulp.Naturally derived fiber suitable for use in this disclosure may include,but are not limited to, rayon, lyocell, and viscose or other materialsderived from natural fibers. For example, lyocell may be derived fromwood pulp, viscose may be derived from wood or cotton fibers, and rayonmay be derived from a wide variety of cellulose-containing naturalfibers. The web of fibers may comprise at least about 80% of cellulosicfibers. The web of fibers may be a paper substrate.

The web of fibers may be formed by water or air or mechanicalentanglement, meltblown, spunbond, thermally or chemically bond. Thefibers may comprise carded, staple, wet laid, air laid and/or spunbondfibers. The web of fibers may be made according to a hydro-entanglingprocess.

Processes to prepare the web of fibers comprising paper include wet-laidpapermaking processes and air-laid papermaking processes, and embossingand printing processes. Such processes typically comprise the steps ofpreparing a fiber composition in the form of a suspension in a medium,either wet, more specifically aqueous medium, or dry, more specificallygaseous (i.e., with air as medium). The aqueous medium used for wet-laidprocesses is oftentimes referred to as a fiber slurry. The fibroussuspension is then used to deposit a plurality of fibers onto a formingwire or papermaking belt such that an embryonic fibrous structure can beformed, after which drying and/or bonding the fibers together results ina fibrous structure. Further processing the fibrous structure can becarried out such that a finished fibrous structure can be formed. Forexample, in typical papermaking processes, the finished fibrousstructure is the fibrous structure that is wound on the reel at the endof papermaking, and can subsequently be converted into a finishedproduct (e.g., a sanitary tissue product). Fibrous structures can bemade by methods known in the art, including by the method and apparatusdescribed in U.S. Pat. No. 4,637,859, issued Jan. 20, 1987, to Trokhan.

In one embodiment, the web of fibers may be degradable. The web offibers may be at least 50% degradable according to ASTM 6400D.

In one embodiment, the web of fibers may have a basis weight of about 10to about 120 gram per square meter, for example from about 15 to 100 orfrom about 20 to about 80 or from about 25 to about 75 or from about 30to about 60 grams per square meter.

In one embodiment, the fibers of the web of fibers may have a diameteror a width of between about 8 microns and about 100 microns. The fibersmay have a length above about 1 mm. The fibers may have a length betweenabout 1 mm and about 5 mm. The fibers, when stapled may have a lengthbetween about 5 mm and about 50 mm. The fibers may be much longer whenspun bond or meltblown.

In one embodiment, the mesh aperture of the web of fibers may be betweenabout 20 microns and about 100 microns.

In one embodiment, the web of fibers may have a thickness between about0.5 mm and about 5 mm, for example between about 1.5 and about 2 mm.

When the nonwoven articles comprises more than one layer of web offibers, one or more than one or each of the web of fibers may be asdefined as above.

The Abrasive Particles

The nonwoven article comprises abrasive particles.

In order to produce particles with desired solidity, the abrasiveparticles may be produced from a foam material, in particular a friablefoam material, but other means such as printing and extruding are alsopossible. The particle or foam material may comprise polyurethane,polyisocyanurate, polyphenolic, polyethylene, polypropylene, polyvinylchloride, polycarbonate, polyacrylate, polystyrene, polyesters,polyamide and mixtures, melamine, urea, minerals and mixtures thereof.

In one embodiment, the abrasive particles are made from biodegradablethermoplastic materials selected the group consisting of biodegradablepolyesters selected from the group consisting of polyhydroxy-alkanoates,such as polyhydroxyButyrate, polyhydroxyButyrate-co-valerate andpolyhydroxyButyrate-co-hexanoate, poly(lactic acid), poly(glycolic),polycaprolactone, polyesteramide, aliphatic copolyesters, aromaticcopolyesters such as co-polyester containing mix of succinic, adipic,terepthalic diacids, propanediol, butanediol, pentanediol monomer andmixtures thereof; thermoplastic starch; polycarboxylic anhydrides andderivatives, cellulose esters particularly cellulose acetate and/ornitrocellulose and their derivatives; and mixtures thereof; for examplea blend of a biodegradable polyester and a thermoplastic starch.

In one embodiment, the abrasive particles may comprise sugar-derivedmaterial e.g.: monomeric or polymeric sugar, especiallyisosorbide-containing materials.

In one embodiment, the abrasive particles may be made from a materialcomprising, or consisting essentially of wax, natural waxes such ascarnauba, candellila, shellac, beewax, etc., or alternatively syntheticwaxes such as montan, microcrystalline, polyethylene-derived wax, etc.,and where the wax or wax blend has a high melting point, typically aboveabout 60° C., an in one embodiment above about 80° C.

In one embodiment, the abrasive particles herein may comprise one ormore mineral materials. Typical mineral materials of interest arederived from carbonate, sulphate, phosphate hydroxide, fluoride salts ofCalcium, Barium, Iron, Magnesium, Manganese, Zinc, Copper, Borate,sodium, potassium, ammonium, alumina or silicate and blends whereas thematerial can be synthesized from extensively known inorganic synthesisprocesses (e.g.: Synthesis of Inorganic Materials—Wiley or Handbook ofInorganic Compounds—CRC) or extracted from mining & processing naturaloccurring inorganic material, alternatively be a mix of synthetic andnatural material.

In one embodiment, the abrasive particles are insoluble in water soeffective scouring is maintained during the total usage of the nonwovenarticle especially when wiping wet soil or wet surfaces, or if thenonwoven article is wetted or rinsed before or during the cleaning work.

In another embodiment, the abrasive particles are partially soluble orsubstantially soluble in water. The solubility of the particle may bechosen so that when wetting occurs, the dissolution kinetic is adjustedto deliver effective scouring before the particles partially or totallydissolve.

In one embodiment, the abrasive particles may be degradable according toASTM 6400D. At least about 50% of the abrasive particles may bedegradable according to ASTM 6400D.

In one embodiment, the abrasive particles may be derived from a naturalsource and may comprise at least about 50% of material derived from anatural source.

In one embodiment, the abrasive particles have a mean solidity belowabout 0.85. In one embodiment, the particles have a mean solidity fromabout 0.3 to about 0.8, or from about 0.35 to about 0.75, or from about0.4 to about 0.7, or from about 0.5 to about 0.65.

In one embodiment, the mean solidity of the particles may be chosen toobtain optimized properties including maintenance of the position of theparticles within the web of fibers, but also cleaning properties andlimitation of the damages to the surface to be cleaned.

In one embodiment, the abrasive particles may have a mean form factorbetween about 0.1 and about 0.6. In one embodiment, the abrasiveparticles have a mean form factor between about 0.1 and about 0.5, orbelow about 0.4, or below about 0.3, or even below about 0.25.

In one embodiment, abrasive having both a mean form factor between about0.1 and about 0.6 and a mean solidity between about 0.3 and about 0.85were particularly suitable. Such parameters may provide non-rolling,sharp particles. Such particles may provide more soil removal whiledamaging less the surface to be cleaned.

In one embodiment, the abrasive particles may have a HV Vickers hardnessfrom 3 to 50 kg/mm².

In one embodiment, the abrasive particles may be produced from materialshaving a Shore® D hardness comprised between 40 and 90.

In one embodiment, the precursor materials of particle abrasives for useherein have a MOHS hardness of from about 1 to about 5.5, or from about1.5 to about 5, or from about 2 to about 5, or from about 2.5 to about3.5.

In one embodiment, the abrasive particles may have a mean EquivalentCircle Diameter (“mean ECD”) ranging from about 20 to about 1000 μm. Theparticles may have a mean ECD ranging from about 75 to about 500 μm, orfrom about 100 to about 300 μm, or between about 150 and about 250 μm.Such particles may provide an optimize cleaning per weight of particlesand/or may be better maintained within the web of fibers.

In one embodiment, the abrasive particles may have a mean ECD rangingfrom about 50 to about 1000%, or from about 80 to about 800%, or fromabout 100 to about 500%, or about 200-400% of the mean ECD of the meshaperture of the web of fibers.

In one embodiment, the abrasive particles may have mean ECD ranging fromabout 5% to about 100%, or from about 10% to about 50%, or from about15% to about 40%, or from about 20 to about 30%, of the thickness of thenonwoven article.

In one embodiment, the abrasive particles may have mean ECD ranging fromabout 5% to about 100%, or from about 10% to about 50%, or from about15% to about 40%, or from about 20 to about 30%, of the thickness of theweb of fibers.

The Nonwoven Article

In one embodiment, the nonwoven article comprises one or more layers ofwebs of fibers, for example from 2 to 4 layers of webs of fibers. Thenonwoven article may comprise from about 85% to about 99.7% or fromabout 95% to about 99% by weight of web of fibers.

In one embodiment, the nonwoven article comprises abrasive particleshaving a mean solidity below about 0.85. The nonwoven article maycomprise from about 0.3% to about 10% or from about 1% to about 3% byweight of abrasive particles having a mean solidity below about 0.85.

In one embodiment, the weight ratio of abrasive particles/web of fibersin the nonwoven articles may be between about 0.003 and about 0.1.

In one embodiment, the nonwoven article comprises from about 0.1 toabout 10 gram of abrasive particles per square meter of the web offibers. In one embodiment, the nonwoven articles comprises from about0.1 to about 5, or from about 0.2 to about 4, or from about 0.25 toabout 2, or from about 0.5 to about 1.5 grams of abrasive particles persquare meter of the web of fibers.

In one embodiment, the abrasive particles may be dispersed randomly onor substantially within the web of fibers. The abrasive particles may bemore concentrated at one or both outer surfaces of the web of fibers.The abrasive particulate may be non-randomly dispersed onto the web offibers in pattern, wherein the pattern covers less than about 30% of oneouter facing surface of the substrates. More than about 40%, or morethan about 60% or about 80%, by weight of the total amount of abrasiveparticles in the web of fibers may be present on less than about 30%, orless than about 20% or less than about 10% of one facing surface of theweb of fibers. In another embodiment ( . . . enumerate higher amounts ofcoverage)

In one embodiment, the abrasive particles may have contrastingappearance to the web of fibers so they are visually noticeable bysimple mean. The Delta L*, and/or the Delta a* and/or the Delta b* maybe above 10, preferably above 20, more preferably above 30 wherein theDelta L*, Delta a*, and Delta b* are respectively the delta of therespective values of the abrasive particulates and the web of fibers.

In one embodiment, the abrasive particles may have similar appearance tothe web of fibers so they are less visually noticeable. The Delta L*,and/or the Delta a* and/or the Delta b* may be below 10, or 5 whereinthe Delta L*, Delta a*, and Delta b* are respectively the delta of therespective values of the abrasive particulates and the web of fibers.

In one embodiment, the abrasive particles may be embedded within the webof fibers. The abrasive particles may be embedded within the web offibers by any means.

In one embodiment, the abrasive particles may be embedded within the webof fibers by entanglement in the web of fibers for example by pre-mixingthe fibers and the abrasive particles before forming the web of fibers.

In one embodiment, the abrasive may be embedded on or substantiallywithin the web of fibers simply depositing the particle at the surfaceof the web and applying mechanical pressure or air pressure, or vacuumor vibration or simply by adjusting the roll winding pressure oralternatively to laminate another web of fibers on top. A particularlyeffective embedding method is via needle punching the fiber web afterdepositing the particles whereby large control of process parameters arepossible to tailor accurately the embedment (cf: Handbook of Nonwoven,S. J. Russell, Woodhead publishing, chap. 5.9)

In one embodiment, the abrasive particle may be deposited onto the webof fibers by mean of vibrating mesh reservoir in dry condition. Theabrasive particles may be deposited onto the web of fibers by airspraying the particles onto the web of fibers also in dry condition. Theabrasive particles may be suspended in a liquid carrier that evaporatesduring or after the deposition process e.g.: whereby water or carbondioxide are good examples. The abrasive particles may be suspended inthe melt of the functional paste. For liquid or melt application,conventional spray, slot or printing processes are suitable.

In one embodiment, the abrasive particles may be embedded on orsubstantially within the web of fibers by melt bonding with fibers. Themelt bonding may take place during the web forming process (e.g.,meltblown-spunbond fibers), during consolidation of the web, or by posttreatment using a blend of fibers having different melting temperatureor by using bicomponent fibers whereby both components having differentmelting temperature.

In one embodiment, the abrasive particles may be embedded in the web offibers by means of an adhesive. In this case, it is critical that theabrasive particles retain a substantial fraction of their shape todeliver effective cleaning. This can be achieved by controlling theamount of adhesive to deliver good bonding with minimal particlecoverage. Alternatively the adhesive can cover the totality of theparticle surface but the adhesive load and spreadable features are suchthat the shape is preserved.

In one embodiment, the nonwoven article may comprise from about 0.03% toabout 5% or from about 0.5% to about 1% by weight of an adhesive. In oneembodiment, the weight ratio of abrasive particles/adhesive in thenonwoven articles may be between about 10 and about 1 or between about 6and about 2. In one embodiment, from 5% to 50% by weight of the abrasiveparticles in the nonwoven article may be embedded in the web of fibersby an adhesive. The adhesive may be waterproof. Exemplary adhesivesinclude: ELVANOL®71-30 8.5%, available from DuPont™, Wilmington, Del.,and AQUANOL LAM 6014 14%, available from Henkel Corporation, Rocky Hill,Conn., USA.

In one embodiment, the abrasive particles may be embedded on orsubstantially within the web of fibers by means of a functional paste.The functional paste must feature significant non-flowing behaviorbefore usage in order to retain dryness and retain the abrasivesparticle but may release both the functional additives and the particlesduring the cleaning operation. In most cases the paste is substantiallysoluble or fully soluble in water so release can occur, especially whencleaning wet soils or wet surfaces or when the dry substrate is wettedor rinsed before or during the cleaning work. The paste may containpreferably a water soluble ligand e.g.: most preferably containingethylene-glycol or vinyl alcohol or acrylamide moieties and functionaladditives such as surfactant, solvent, buffer systems especially base oncitric and/or baking soda, perfume, biocides, etc, with or withoutadhesives. Since the paste is preferably water soluble, it may coverfully or partially the abrasive particles. Preferable paste-to-abrasiveweight ratio range from about 0.3 to about 5.

In one embodiment, the nonwoven article may comprise from about 1% toabout 10% of paste/abrasive particle mix. In one embodiment, thenonwoven article may comprise from about 1 to about 10 gram ofpaste/abrasive particles mix per square meter of the web of fibers, orfrom about 1 to about 5, or from about 2 to about 4 grams ofpaste/abrasive particles mix per square meter of the web of fibers.

In one embodiment, the abrasive particles may be deposited onto the webof fibers by air spraying the particles onto the web of fibers. Theabrasive particle may be deposited onto a web of fibers while anadhesive composition is simultaneously sprayed. The web of fibers may bepretreated with an adhesive on a surface of the web. Heating, pressureor a combination thereof may be applied to provide the desired adhesionof abrasive particles to the web.

In one embodiment, the nonwoven article may be disposable. Disposable isused in its ordinary sense to mean an article that is disposed ordiscarded after a limited number of usage events, preferably less than25 or less than 10 or less than 2 usage events.

In one embodiment, the nonwoven article may have a length of from about5 to about 60 cm, or from about 10 to about 20 cm, a width of from 5 toabout 30 cm, or from about 10 to about 20 cm.

In one embodiment, the nonwoven article may have a thickness betweenabout 0.5 mm and about 10 mm, for example between about 2 and about 5mm.

In one embodiment, the nonwoven article is dry. By dry it is meant thatthe article does not comprise more than about 5% by weight of a liquid.The article may exhibit a moisture retention of less than about 3 grams,or less than about 1 gram or less than about 0.25 g or less than about0.1 g before usage. The nonwoven article may be dry-to-the-touch. By“dry-to-the-touch” it is meant that the nonwoven article are free ofwater or other solvents in an amount that would make them feel damp orwet to the touch. The article may comprise less than about 3% or lessthan about 1% by weight of liquid. The article may comprise less thanabout 5%, or less than about 3%, or less than about 1% by weight ofwater.

In one embodiment, the nonwoven article may comprise an additive. Theadditive may improve cleaning performance and/or enhance the cleaningexperience. The additive may comprise wax, such as microcrystalline wax,oil, adhesive, perfume and combinations thereof.

In one embodiment, the nonwoven article may be pre-moistened. Thenonwoven article may comprise a liquid. The nonwoven article maycomprise at least about 1%, or at least about 3%, or at least about 5%,by weight of a liquid. The liquid may provides improved cleaning of atarget surface, such as a floor. The liquid may not require apost-cleaning rinsing operation. The nonwoven article may be loaded withat least about 1, 1.5 or 2 grams of liquid per gram of dry substrate,but typically not more than about 5 grams per gram. The liquid maycomprise a surfactant, such as APG surfactant, agglomerating chemicals,disinfectants, bleaching solutions, perfumes, secondary surfactants etc.

In one embodiment, the nonwoven article may comprise layers, to providefor absorption and storage of cleaning fluid deposited on the targetsurface. If desired, the nonwoven article may comprise absorbent gellingmaterials to increase the absorbent capacity of the nonwoven article.The absorbent gelling materials may be distributed within the nonwovenarticle in such a manner to avoid rapid absorbency and absorb fluidsslowly, to provide for the most effective use of the nonwoven article.

In one embodiment, the nonwoven article may comprise one or more webs offibers disposed in a laminate. The lowest, or downwardly facing outerlayer, may comprise apertures to allow for absorption of cleaningsolution therethrough and to promote the scrubbing of the targetsurface. Intermediate layers may provide for storage of the liquids, andmay comprise the absorbent gelling materials. The nonwoven article mayhave an absorbent capacity of at least about 10, 15, or 20 grams ofcleaning solution per gram of dry nonwoven article, as set forth incommonly assigned U.S. Pat. Nos. 6,003,191 and 6,601,261. The top, orupwardly facing outer layer, may be liquid impervious in order tominimize loss of absorbed fluids. The top layer may further provide forreleasable attachment of the nonwoven article to a cleaning implement.The top layer may be made of a polyolefinic film, such as LDPE. Theouter layer of web of fibers may have a basis weight of about 5 to 30gram per square meter, for example from about 10 to 20 grams per squaremeter. Such basis weight has been found to be particularly suitable whenthe abrasive particles are between the outer layer and another web offibers.

In one embodiment, the nonwoven article may be used with a stick-typecleaning implement. The cleaning implement may comprise a plastic headfor holding the cleaning sheet and an elongate handle articulableconnected thereto. The handle may comprise a metal or plastic tube orsolid rod. A suitable stick-type cleaning implement may be madeaccording to commonly assigned U.S. Pat. Nos. Des. 391,715; D409,343;D423,742; D481,184; D484,287; D484,287 and/or D588,770. A suitablevacuum type cleaning implement may be made according to the teachings ofU.S. Pat. Nos. 7,137,169, D484,287 S, D615,260 S and D615,378 S. Amotorized implement may be made according to commonly assigned U.S. Pat.No. 7,516,508.

In one embodiment, the cleaning implement may further comprise areservoir for storage of cleaning solution. The reservoir may bereplaced when the cleaning solution is depleted and/or refilled asdesired. The reservoir may be disposed on the head or the handle of thecleaning implement. The neck of the reservoir may be offset per commonlyassigned U.S. Pat. No. 6,390,335. The cleaning solution containedtherein may be made according to the teachings of commonly assigned U.S.Pat. No. 6,814,088.

The Surface to be Cleaned

The invention also concerns a process to clean a surface with thearticle of the invention.

The nonwoven article may be used to clean a surface. The surface may beinanimate or animate, such as household hard surface, dish surfaces,hard and soft tissue surface of the oral cavity, such as teeth, gums,tongue and buccal surfaces, human and animal skin, hair.

By “household hard surface”, it is meant herein any kind of surfacetypically found in and around houses like kitchens, bathrooms, e.g.,floors, walls, tiles, windows, cupboards, sinks, showers, showerplastified curtains, wash basins, WCs, fixtures and fittings and thelike made of different materials like ceramic, vinyl, no-wax vinyl,linoleum, melamine, glass, Inox®, Formica®, any plastics, plastifiedwood, metal or any painted or varnished or sealed surface and the like.Household hard surfaces also include household appliances including, butnot limited to refrigerators, freezers, washing machines, automaticdryers, ovens, microwave ovens, dishwashers and so on. Such hardsurfaces may be found both in private households as well as incommercial, institutional and industrial environments.

By “dish surfaces” it is meant herein any kind of surfaces found in dishcleaning, such as dishes, cutlery, cutting boards, pans, and the like.Such dish surfaces may be found both in private households as well as incommercial, institutional and industrial environments.

In one embodiment, the process may include a step of wetting thenonwoven article before the cleaning step with water, an aqueouscomposition, a solvent composition, and/or a composition comprising asurfactant.

EXAMPLES Example 1

Hard surface wipe: abrasive particles are loaded on a vibrating grid of15 mesh before depositing by gravity at the surface of a nonwoven acrossthe full surface targeting a particle load of about 0.5 gram per squaremeter. Abrasive particles are made from polyurethane foam, saidparticles having Mean Area-equivalent Diameter (ECD) of about 238 μm andMean Solidity of about 0.59. The non-woven material is a cardedhydroentangled substrate of about 58 g/m2, consisting of about 60%polypropylene and about 40% viscose fibers of a dry thickness of about0.57 mm.

Example 2

Hard surface wipe: Abrasive particles are air-sprayed at the surface ofa nonwoven across the full surface using sandblasting spraying nozzle atabout 1 bar to achieve effective particle embedding at the surface.Abrasive particles made from polyurethane foam, said particles havingMean Area-equivalent Diameter (ECD) about: 280 μm and Mean Solidity ofabout 0.77. The non-woven material is a carded hydroentangled substrateof about 58 g/m2, consisting of about 60% polypropylene and about 40%viscose fibers of a dry thickness of about 0.57 mm.

Example 3

Hard surface wipe: as in example 2 except that the abrasive material ismade of PolyhydroxyButyrate-co-valerate foam, and has MeanArea-equivalent Diameter (ECD) of about: 220 μm and Mean Solidity ofabout 0.83.

Example 4

Hard surface wipe: abrasive particles are loaded on a vibrating grid of15 mesh before depositing by gravity at the surface of a nonwoven acrossthe full surface targeting a particle load of about 0.5 gram per squaremeter. A needle-punching process is applied prior to winding in order tofurther embed the abrasive particle in the fiber web (needle fosterformed barb gauge 20, needle board density about 20,000/m2, about 15,000punch/min.). Abrasive particles are made from polyurethane foam, saidparticles having Mean Area-equivalent Diameter (ECD) of about 307 μm andMean Solidity of about 0.63 and a form factor of about 0.16. Thenon-woven material is a carded hydroentangled substrate of about 58g/m2, consisting of about 60% polypropylene and about 40% viscose fibersof a dry thickness of about 0.57 mm.

Example 5

Floor wipe: abrasive particles are loaded on a vibrating grid of 15 meshbefore depositing by gravity at the surface of a nonwoven to form adiscontinuous strip of particles whereby the particle load on thatstripe is about 1 gram per square meter and the stripe width is about 3cm, representing about 12% of the floor wipe total surface andneedlepunching as in example 3 is applied on the stripe. Abrasiveparticles are made from polyurethane foam, said particles having MeanArea-equivalent Diameter (ECD) of about 216 μm and Mean Solidity ofabout 0.66. The non-woven material is a carded hydroentangled substrateof about 98 g/m2e, consisting of about 60% polypropylene and about 40%viscose fibers of a dry thickness of about 0.82 mm prior toneedlepunching.

Example 6

Toilet flushable wipe: about 2 parts of abrasive particles are mixedwith about 85 parts of cellulosic fibers and about 15 parts ofstyrene-butadiene resin binder in an air-laid latex bond web-formingprocess yielding a substrate of about 50 gram per square meter, of about0.45 mm dry thickness. Cellulose fibers are mix of natural and syntheticcellulose fibers (about 40% Hardwood kraft fibers, about 40%, Eucalyptusfibers, and about 20% lyocell fibers). Abrasive particles are made fromPolyhydroxyButyrate-co-valerate foam, said particles having MeanArea-equivalent Diameter (ECD) of about 220 μm and Mean Solidity ofabout 0.83.

Example 7

Baby toilet wipe: about 2 parts of abrasive particles are mixed withabout 40 parts of viscose fibers, about 33 parts of woodpulp and about22 parts polyethylene tetraphthalate fibers in hydoentlangled, resinbond process yielding a substrate of about 70 gram per square meter andabout 0.55 mm thickness. Abrasive particles are made fromPolyhydroxyButyrate-co-valerate foam, said particles having MeanArea-equivalent Diameter (ECD) of about 320 μm and Mean Solidity ofabout 0.81.

Example 8

Disposable Hard surface towel: an abrasive-containing paste is appliedby gravure printing process on a disposable paper substrate in adiscontinuous pattern whereby about 200 mg of paste is deposited perwipe in a printed pattern covering about 20% of the wipe area. Each wipehas dimensions of: 278×262 mm. The paste contains about 22% of abrasiveparticles (from PU foam, said particles having Mean Area-equivalentDiameter (ECD) of about 307 μm and Mean Solidity of about 0.63 and aform factor of about 0.16), about 20% greenbentin D0/80 (nonionicsurfactant), about 20% of Euro Surflex 1213 (anionic surfactant), about18% of C12-14 alkyl dimethyl amine-oxide and about 20% of Polyethyleneglycol 8000. The about 60 gram per square meter, and about 0.6 mm drythickness fiber web is made of about ⅓ Eucalyptus fibers, about ⅓Hardwood kraft fibers and about ⅓ Hardwood sulfite fibers

Example 9

disposable towel: Abrasive particles are air-sprayed at the surface of apaper substrate across the full surface using sandblasting sprayingnozzle at about 1 bar to achieve effective particle embedding at thesurface. Abrasive particles made from polyurethane foam, said particleshaving Mean Area-equivalent Diameter (ECD) about: 280 μm and MeanSolidity of about 0.77. The paper substrate is about 58 grams per squaremeter, and about 0.65 mm dry thickness fiber web and is made of about46% Eucalyptus fibers, about 13% Hardwood kraft fibers and about 41%Hardwood sulfite fibers

Example 10

disposable towel: Material is as example 8, but about 10 grams persquare meter of cellulosic fiber web is deposited by airlaid depositionresin bond process on the substrate.

Example 11

disposable towel: Material is as example 8, but about 5 grams per squaremeter of polypropylene fiber web is deposited by spunbond process on thesubstrate.

Example 12

disposable towel: Abrasive particles are mixed at about 15% w with adilute water-soluble adhesive; this mixture is then applied to a 26grams per square meter paper ply in a dot pattern to about 5% of thesheet area at a loading of about 350 grams per square meter within thatpattern. Another 26 grams per square meter paper ply is introduced aboveand embossing plates matching the dot pattern are used to compress theplys together. The laminated sheet is dried to remove water. Abrasiveparticles are made from polyurethane foam having Mean Area-equivalentDiameter (ECD): about 280 μm and Mean Solidity of about 0.77. The 26grams per square meter, fiber web plys are made of about 46% Eucalyptusfibers, about 13% Hardwood kraft fibers and about 41% Hardwood sulfitefibers. The water-soluble adhesive may be AQUANOL® LAM 6014 (14% activepolyvinyl alcohol) or ELVANOL® 71-30 (8.5% active polyvinyl alcohol).

The dimensions and values disclosed herein are not to be understood asbeing strictly limited to the exact numerical values recited. Instead,unless otherwise specified, each such dimension is intended to mean boththe recited value and a functionally equivalent range surrounding thatvalue. For example, a dimension disclosed as “40 mm” is intended to mean“about 40 mm”.

Every document cited herein, including any cross referenced or relatedpatent or application and any patent application or patent to which thisapplication claims priority or benefit thereof, is hereby incorporatedherein by reference in its entirety unless expressly excluded orotherwise limited. The citation of any document is not an admission thatit is prior art with respect to any invention disclosed or claimedherein or that it alone, or in any combination with any other referenceor references, teaches, suggests or discloses any such invention.Further, to the extent that any meaning or definition of a term in thisdocument conflicts with any meaning or definition of the same term in adocument incorporated by reference, the meaning or definition assignedto that term in this document shall govern.

While particular embodiments of the present invention have beenillustrated and described, it would be obvious to those skilled in theart that various other changes and modifications can be made withoutdeparting from the spirit and scope of the invention. It is thereforeintended to cover in the appended claims all such changes andmodifications that are within the scope of this invention.

What is claimed is:
 1. A dry nonwoven article comprising a web of fibersand abrasive particles, wherein the abrasive particles have a meansolidity below about 0.85.
 2. The article according to claim 1, whereinthe abrasive particles are embedded in the web of fibers.
 3. The articleaccording to claim 1, wherein the abrasive particles have a meansolidity between about 0.3 and about 0.8.
 4. The article according toclaim 1, wherein the abrasive particles have a mean form factor betweenabout 0.1 and about 0.6.
 5. The article according to claim 1, whereinthe abrasive particles have a mean ECD between about 20 and about 1000microns and between about 5% and about 100% of the thickness of the webof fibers.
 6. The article according to claim 1, wherein the underlyingmaterial of the abrasive particles has a mean Shore D® hardness betweenabout 40 and about
 90. 7. The article according to claim 1, wherein theweb of fibers comprises from about 0.1 to about 10 grams per squaremeter of abrasive particles.
 8. The article according to claim 1,wherein at least about 50% of the abrasive particulate is degradableaccording to ASTM 6400D.
 9. The article according to claim 1, whereinthe nonwoven article is made of at least 2 superposing webs of fibersdisposed in a face-to-face relationship and the abrasive particles arelocated at the webs face-to-face interfaces.
 10. The article accordingto claim 1, wherein the abrasive particles are produced from a friablefoam material comprising polyurethane, polyisocyanurate, polyphenolic,polyethylene, polypropylene, polyvinyl chloride, polycarbonate,polyacrylate, polystyrene, polyesters, polyamide and mixtures, melamine,urea, minerals and combinations thereof.
 11. The article according toclaim 1, wherein the abrasive particles have a mean ECD ranging fromabout 20 to about 1000 microns according to ISO 9276-6.
 12. The articleaccording to claim 1, wherein the abrasive particles have a mean ECDfrom above about 5% to below about 100% of the thickness of the drysubstrate
 13. The article according to claim 1, wherein the abrasiveparticles have a HV Vicker hardness from about 20 to about
 100. 14. Thearticle according to claim 1, comprising between 2 and 4 web of fibers.